I found oil in one of the spark plug tubes a while back (in the rear bank, of course), and I figured one of the grommet seals had gone bad. So I've got it apart, but the grommet looks fine, and there's no evidence of oil around the top of the tube. It first shows up about halfway down. I suppose it could be dripping from the center and, since the tube is at an angle, not hitting the inside of the tube until part way down. But now that I've got it apart, I want to make sure I'm not missing something.

Anyone know if there's anything else that could cause oil to appear in the tube? Should I be looking for another suspect?

 

What parts did you remove to get to the grommet? I have a leak in the leftmost spark plug tube (rear)...Anyone?